Nozzle construction



MalCh 18, Q R WALLER NOZZLE CONSTRUCTION Filed Oct. 28. 1927 ausV Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE CARL R. WALLER, TRENTON, NEW JERSEY, ASSIGNOR TO DE LAVAL STEAM TUR- BINE COMPANY, 0F TRENTON, NEW JERSEY, A CORPORATION 0F NEW JERSEY NOZZLE CONSTRUCTION Application. led October 28, 1927.

This invention relates to an improved nozzle for an elastic fluid turbine and especially to a nozzle structure which is formed of a plurality of assembled parts. There are three possible methods which may be utilized for mak-ing the nozzle elements in a turbine, namely, drilling the nozzle passages in a solid block of metal, casting partitions in a dia phragm to form nozzle passages, or assembling machined parts, which together will form nozzle passages. The first method does not lend itself readily to the formation of pas sages of maximum efficiency. The second method can only be utilized when the size of the nozzles are large enough to allow a core to be made at the time the nozzle elements are cast into the walls of the diaphragms. The third method is by far the mostideal as it will produce nozzle passages the shape of which can be made of the proper finish to insure the maximum of nozzle eiiciency.

In constructing a built up nozzle, however, it is essential that when the machined parts are assembled, the struct-ure should be steam tight except for the nozzle passage, since otherwise leakage may take place and the high pressure steam, moving with a high velocity, will quickly destroy the structure.

The object of the present invention is a provision of a built up nozzle structure in which joints between the various parts may be readily made steam tight.

In the drawing:

Fig. 1 is a sectional view showing one form of nozzle structure and taken on the radial plane indicated by line 1 -1 of Fig. 2.

Fig. 2 is an elevation located at the right of Fig. 1.

Fig. 3 is a section through the vanes taken on line 3 3 of Fig. 2.

Fig. 4 is a view similar to Fig. 1, showing a modification, and

Fig. 5 is a View similar to Fig. 1, showing a further modification.'

A nozzle carrying member 2, which may be either the wall of the steam chest of a turbine or a diaphragm, is provided with an opening 4 through which steam is adapted to pass through a nozzle to rotate rotor 6 by impact with blades 8. A semi-circular ring Serial No. 229,313.

10 is secured to member 2 by means of bolts 12 and has an upper surface extending eircumferentially about the axis of a turbine. shaft and in close relationship to blades 8. Upon the circumferential surface ofmember 10 are carried vanes 14, secured thereto as shown in Fig. 2 by means of pins 16, which maintain them in proper position, relatively to the rotor blades. 'Ihese vanes 14 may be suitably shaped to provide passages of maximum efficiency. Contacting' with the outer surfaces of vanes 14 is the inner surface of a semi-circular ring 18, secured to member 2 by a bolt 20. The inner and outer surfaces of vanes 14 are shaped t'o correspond to the surfaces of members 10 and 18 contacting therewith, in order to form a steam tight joint.

In order to insure an absolutely steam tight joint, member 18 is provided along its inner edge with a tapered groove 22 in to which a tapered wedge 24 may be driven to force inwardly the inner surface of member 18 tightly against the out-er surface of the vanes, the resiliency of that portion of member 18 be tween groove 22 and the outer surface of the vanes being sufficient to allow some slight movement thereof. The edges of members 10 and 18 are bevelled as shown at 26 and 28, to provide proper entrance for the steam into the nozzles.

In the modification shown in Fig. 4, a ring 32, somewhat similar to ring 10, is provided within a countersunk portion 30 of member 2 and secured therein by bolts 34. Vanes 36 are carried by ring 32 in a manner similar to the vanes in the modification of Fig. 1. In this modification, no separate member such as 18 is provided to contact with the outer surface of the vanes but member 2 itself is provided with a ltapering groove 40, adjacent a surface thereof contacting with the vanes into which groove the wedge 42 may be driven to force the portion of member 2 in contact with the vanes thereagainst.

In the modification shown in Fig. 5, a surface 44 of member 2 is arranged to contact with the outer surfaces of vanes 46 which are carried by a. ring 48, mounted in a cut-away portion 50 of member 2. The inner surface of member 48 is tapered relatively to the opposed surface of cut-away portion 50 to provide a space into which a wedge 52 may be driven to cause 48 to move outwardly and compress vanes 46 into close enga-gement with the surface 44. vWedge 52 may be secured irremovably in place by means of welding 54, to receive which, the adjacent edges of 52 and 2 may be bevelled as shown in Fig. 5.

W'hile three modifications disclosing the practical applications of this invention have been shown, it will be readily understood that various changes may be made while still retaining the advantageous results obtained by 5 utilization of the principles of this invention, for example, .in the modification shown in Fig. l, blades 14 might be formed integrally with the surfaces adjacent thereto or they may be supported removably thereon. It

will be observed, however, that in every case there is produced a wall which is movable toward a second wall to compress a vane therebetween and thus insure a steam tight contact between the vane and the walls on either side thereof. Further, while an ordinary tapered wedge has been disclosed in each of the modifications, it will be apparent that a similar means, such as a screw, might be substituted therefor to force the walls toward 0 each other.

lVhat I claim and desire to protect by Letters APatent is:

l. A nozzle construction for turbines comprising a vane supporting structure having opposed circumferentially extending walls forming a passage therebetween, a vane located in said passage and between said walls, and means formoving one of said walls towards the other to tightly clamp the vane therebetween, said means Vcomprising a surface on the wall tapering relatively to a fixed surface, the angle between the surfaces opening in a direction substantially parallel to the walls, and a wedge engaging between said surfaces.

2. A nozzle construction for turbines comprising a vane supporting structure having opposed circumferentially extending walls forming a passage therebetween, a vane located in said passage and between said walls, said vane having surfaces corresponding in shape to said walls to fit tightly thereagainst, and means for moving one of said walls towards the other to engage the surfaces of the 5 vane with said walls, said means comprising a surface on a wall tapering relatively to a fixed surface, the angle between the surfaces opening in a direction substantially parallel to the walls, and a wedge engaging between said surfaces.

3; A nozzle construction for turbines comprising a vane supporting structure having opposed circumferentially extending walls forming a passage therebetween, a vane located in said passage and between said walls,

one of said walls being formed on a member.integrally joined at its base to a fixed element, and means for flexing said member relatively to said fixed element to move the wall thereon towards the other wall to tightly clamp the vane therebetween.

4. A nozzle construction for turbines comprising a vane supporting structure having opposed circumferentially extending walls forming a passage therebetween, a vane lo cated in said passage and between said walls` one of said walls being formed on a member integrally joined at its base to a fixed element, said member and element having opposed tapering surfaces, and a wedge engaging between said surfaces and adapted to flex said member relatively to said fixed element to move the wall thereon towards the other wall to tightly clamp the vane therebetween.

In testimony of which invention, I have 

